Centroid Community CNC Support Forum

Guys,
Just wanted to post some information on how to get the Acorn to control some Panasonic Servo drivers. There are various kinds of Panasonic drivers but the information I am posting handles the drivers with model numbers similar to MSD011A1XX14, etc. The power output of the amplifiers will vary from 50W, 100W, 200W, 400W, or 750W. These type drivers have a 36-pin connector for CN-I/F which is the control input connector for these drivers.
I have updated one of the Centroid drawings to reflect the connections on these type amplifiers.

These amplifiers must be configured by changing some parameters in the driver or they will not work. The critical parameters are listed in the panasonic.txt file that I have attached.

These older Panasonic drivers and servo are readily available on ebay and work great. I have attached the Panasonic manual for these type drivers as they are getting hard to locate on the internet. It is a really good idea to read through the manual and learn how to set parameters in these drivers. These drivers come with a built in display making changing parameters very easy. They also have a built in tuning algorithm that allows the driver to tune itself to the servo and you can select the stiffness required.

One note, most Panasonic or Yaskawa and many other drivers are setup to accept differential signals. The reason is this type interface is more noise immune. You can drive them using singled ended drivers like the Acorn, but I actually built a little board that converts from single ended to differential to take advantage of the noise immunity. The other thing is differential inputs can run much faster than single ended inputs, however the Acorn is limited to 200KHz step speeds so that is probably not a concern.<<< cnckeith writes... Russ the Acorn has user selectable 200 or 400 KHz output, its in the Wizard on the Advanced Tab.>>>

Let me know if you have questions. Now that I have completed bench testing the Acorn I will start putting it all together in a new enclosure and then bolt it up to my machine. Goodbye Mach3 forever. LOL

Russ

Thank you very much for sharing your information. I'm sure your efforts will be appreciated by others in the forum and we look forward to seeing more from you as your project progresses.

Well I spent a good deal of time this weekend wiring up the Centroid Acorn in its enclosure. I wish I had purchased a larger enclosure as there was not enough room in the room I have to install the servo drivers for four axis as well as the other items. So I will mount the drivers right next to the enclosure or possible get another small enclosure for the drivers and VFD.

I custom built the Servo CN-I/F cables using some Alpha Wire 25129 SupraShield Extragard cable. This stuff is very noise immune if you wire it up correctly. I did not really need all the wires on this application but some of the signals I used for some future use after I get everything else working.
The assignment for signals is detailed in the attached power point drawing.

https://www.ebay.com/itm/Alpha-Wire-251 ... SwxH1T47hH

The machine I am attaching this is a 2x2 machine I built myself, and it will hold a 3KW water cooled spindle. I have been rewiring everything and this takes some time. I use braided shielded wires for all cables to avoid all the EMI headaches that often follow if you fail to ground things properly to avoid that interference. I also installed a different Mean Well power supply that had 5,12, and 24V outputs, which allows me to power the differential driver board and the 12V will be used for a ring light that mounts around the spindle to illuminate what your cuttings. I also run the AC power that enters the enclosure through an illuminated rocker switch into a EMI filter.

Won't get much done for the next two weeks headed out on vacation. Hope to have the machine all back and running shortly after I return.

Russ

Nice work and tip on the Panasonic drives Russ.
Thanks for sharing the info. We'll be watching in 2.1 weeks to see the machine cutting.
Marty

Terry at Arrow Controls posted this video on Facebook showing his Acorn installation using Panasonic motors and drives.

Thanks for sharing Keith,

Yeah mine is rock solid with the Acorn and Panasonic servos. Noticed they also used differential drivers, looks like the ones from CNCPC, I ended up just using the CNC machine to cut some copper PCBs and made my own.

Nice Job Arrow Controls.

Russ

cncman172 wrote: ↑Thu Nov 02, 2017 4:23 pm .
.., but I actually built a little board that converts from single ended to differential to take advantage of the noise immunity. ...
.

I am not very familiar with the terminology. Is differential the same as Quadrature? See image below of the A and B inputs. Top views the motor turning in one direct and the bottom shows turning in the other direction.
. .
The reason I am asking is because I have a MaxNC that requires Quadrature input instead of Step and Direction and I was wondering if the board you made would work for me.

Currently I am running the Minas A4 and A6 drivers and am able to connect without using line drivers. My machine is not finished yet, someone else reported getting instability, so lets see if this works longer term.

Differential and quadrature are not the same thing. Differential means that one wire carries a positive pulse while the second wire in the pair carries a negative pulse. Single ended signals have one wire with a positive pulse and the other wire is ground. Differential and line driver often mean the same thing when referring to encoders.

Quadrature is a method of encoding velocity and direction information in the series of pulses on two different channels.

doucetw wrote: ↑Tue Mar 19, 2019 3:55 pm

cncman172 wrote: ↑Thu Nov 02, 2017 4:23 pm .
.., but I actually built a little board that converts from single ended to differential to take advantage of the noise immunity. ...
.

I am not very familiar with the terminology. Is differential the same as Quadrature? See image below of the A and B inputs. Top views the motor turning in one direct and the bottom shows turning in the other direction.
.
288476-decode_a_quadrature_encoder_in_software_figure_1.gif
.
The reason I am asking is because I have a MaxNC that requires Quadrature input instead of Step and Direction and I was wondering if the board you made would work for me.

Your best bet is to swap over to standard stepper drivers as I suggestioned before.
automationtechnologiesinc.com is a good source.
Marty